Clinical characteristics and treatment patterns in patients with atherosclerotic cardiovascular disease with hypercholesterolemia: a retrospective analysis of a large US real-world database cohort

OBJECTIVE

Guidelines developed by the American College of Cardiology/American Heart Association (ACC/AHA) recommend lipid-lowering therapies (LLTs) to reduce low-density lipoprotein cholesterol (LDL-C) and atherosclerotic cardiovascular disease (ASCVD) risk. This study described LLT utilization patterns and LDL-C goal achievement (to <70 mg/dL) among patients with ASCVD in the United States.

METHODS

This retrospective study was conducted using Optum's de-identified Clinformatics Data Mart Database (CDM). Patients with their first ASCVD diagnosis (index date) in the CDM database between July 1, 2015, and December 31, 2018, were followed for ≥12 months to assess LLT utilization patterns and change in LDL-C. LLTs included were statins and non-statin LLTs (ezetimibe, fibrates, and proprotein convertase subtilisin/kexin type 9 inhibitors). Adherence was measured as the proportion of days covered (PDC), defined as the number of days with drug on-hand (or number of days exposed to drug) divided by the 12-month follow-up period. Patients with PDC ≥0.8 were considered adherent.

RESULTS

Among the patients with ASCVD (N = 1,424,893) included in this study, only 621,978 (43.7%) had at least one LDL-C measurement at baseline (6 months prior to and 3 months after the index date). The mean age was 71.5 years, and almost half of the patients were female. Patients were followed for a mean (standard deviation [SD]) duration of 30.6 (11.4) months (median of 29.9 months). During the follow-up, about one-quarter of the patients did not receive any LLT. Among treated patients, 89.5% received statins and 10.5% received non-statin LLT. Less than half (47.6%) of the patients were adherent to the index treatment during the 12-month follow-up. Even in patients receiving combination therapy (statin + non-statin LLT), a sizable proportion (35.8%) showed an increase in LDL-C over the follow-up period.

CONCLUSIONS

This retrospective study highlighted limited LDL-C monitoring in patients with ASCVD, and unmet need in terms of suboptimal utilization of non-stain LLTs, limited adherence to LLTs, and inadequate lipid control after treatment (among those with LDL-C measurements during the follow-up period) need to be addressed to improve outcomes in this patient cohort.

Nationwide trends in hospitalization, medical costs, and mortality for asthma after introduction of biologics: A cross-sectional study in the United States

BACKGROUND: Asthma is the most common inflammatory lung disease in the United States. Since 2015, biologic therapies have provided targeted treatment for patients with severe asthma. OBJECTIVE: To evaluate the trends for in-hospital outcomes of asthma before (2012-2014) and after (2016-2018) the introduction of biologic therapies for asthma. METHODS: We conducted a nationwide cross-sectional analysis of patients aged 2 years or older who were hospitalized for asthma between 2012 and 2018 using data from the Nationwide Readmissions Database. Outcomes included rates of asthma hospital admission and asthma-related 30-day readmission, hospital length of stay, hospital costs, and inpatient mortality. Generalized linear models assessed trends in rates of asthma admission and readmission, length of stay, costs, and mortality quarterly during 2012-2014 and 2016-2018. RESULTS: Among 691,537 asthma-related admissions, quarterly asthma admission rates significantly decreased (-0.90%, 95% CI = -1.46% to - 0.34%; P = 0.002) during 2016-2018, mainly among adults, but not during 2012-2014. Quarterly assessed readmission rates decreased by 2.40% (-2.85% to -1.96%; P < 0.0001) during 2012-2014 and by 2.12% (-2.74% to - 1.50%; P < 0.0001) during 2016-2018. Mean length of stay for asthma admissions decreased quarterly by 0.44% (-0.49% to - 0.38%; P < 0.0001) during 2012-2014 and by 0.27% (-0.34% to - 0.20%; P < 0.0001) during 2016-2018. Quarterly hospital costs for admissions were unchanged during 2012-2014 but increased by 0.28% (0.21% to 0.35%; P < 0.0001) during 2016-2018. There were no significant trends in inpatient mortality during 2012-2014 and 2016-2018. CONCLUSIONS: After the introduction of new biologics for severe asthma in 2015, asthma-related hospital admissions decreased significantly, whereas hospital costs increased. Asthma-related 30-day readmission rates and length of stay for asthma admissions continuously decreased, whereas inpatient mortality rates remained stable. DISCLOSURES: This work was supported by the National Heart, Lung, And Blood Institute of the National Institutes of Health under Award Number R01HL136945. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health. The data that support the findings of this study are available from the Agency for Healthcare Research and Quality's Healthcare Cost and Utilization Project but restrictions apply to the availability of these data, which were used under license for the current study, and so are not publicly available. Data are however available from the authors upon reasonable request and with permission of the Agency for Healthcare Research and Quality's Healthcare Cost and Utilization Project.

Characteristics and lipid lowering treatment patterns in patients tested for lipoprotein(a): A real-world US study

Objective

Elevated lipoprotein(a) [Lp(a)] is a risk factor for atherosclerotic cardiovascular disease (ASCVD) and has no approved pharmacotherapies. Limited real-world data exists on the proportion of patients with available Lp(a) test results, characteristics of these patients, and their use of lipid lowering therapies (LLTs) for secondary prevention (SP) and primary prevention (PP) of ASCVD.

Methods

Patients with measured Lp(a) receiving LLTs for SP or PP of ASCVD were identified in the Optum Clinformatics® Data Mart database. Lp(a) distribution and LLT utilization including persistence and adherence were assessed. Logistic regression was used to assess the association between Lp(a) levels and low-density lipoprotein cholesterol (LDL-C) levels after index LLT, adjusting for baseline characteristics.

Results

Overall, 2154 SP and 7179 PP patients met eligibility criteria. Of patients with available laboratory data, only 0.7% (SP) and 0.6% (PP) had Lp(a) test results. In the SP cohort, Lp(a) levels ≥125 nmol/L and ≥175 nmol/L were 26.4% and 17.6%, respectively, and the mean (SD) Lp(a) levels (overall SP cohort 90.4 [97.9] nmol/L) were highest in Black patients (123.4 [117.4]; p<0.001). Statin monotherapy was the most frequently prescribed LLT in SP patients overall (89.4%). Median (interquartile range [IQR]) persistence of LLTs was 227 (91, 649) days and 33.6% achieved ≥80% proportion of days covered (PDC). Patients with Lp(a) ≥175 nmol/L had 2.1 times greater odds of having elevated LDL-C (≥70 mg/dL) post-LLT than those with Lp(a) <175 nmol/L (p = 0.031). Similar findings were observed in the PP population.

Conclusions

Lp(a) screening was rare. Elevated Lp(a) was observed in more than one-quarter of patients receiving LLTs, with the highest mean Lp(a) levels observed in Black patients. Low adherence to LLTs was prevalent and at least half of patients failed to achieve their respective LDL-C target thresholds despite treatment. Finally, high Lp(a) levels were associated with worse LDL-C control.

Antihypertensive Use and the Risk of Alzheimer's Disease and Related Dementias among Older Adults in the USA

BACKGROUND

Epidemiological evidence on different classes of antihypertensives and risks of Alzheimer's disease and related dementias (ADRD) is inconclusive and limited. This study examined the association between antihypertensive use (including therapy type and antihypertensive class) and ADRD diagnoses among older adults with hypertension.

METHODS

A retrospective, cross-sectional study was conducted, involving 539 individuals aged ≥ 65 years who used antihypertensives and had ADRD diagnosis selected from 2013 to 2018 Medical Expenditure Panel Survey (MEPS) data. The predictors were therapy type (monotherapy or polytherapy) and class of antihypertensives defined using Multum Lexicon therapeutic classification (with calcium channel blockers [CCBs] as the reference group). Weighted logistic regression was used to assess the relationships of therapy type and class of antihypertensives use with ADRD diagnosis, adjusting for sociodemographic characteristics and health status.

RESULTS

We found no significant difference between monotherapy and polytherapy on the odds of ADRD diagnosis. As to monotherapy, those who used angiotensin-converting enzyme inhibitors (ACEIs) had significantly lower odds of developing AD compared to those who used CCBs (OR 0.36, 95 % CI 0.13-0.99).

CONCLUSIONS

Findings of the study suggest the need for evidence-based drug therapy to manage hypertension in later adulthood and warrant further investigation into the mechanism underlying the protective effect of antihypertensives, particularly ACEIs, against the development of AD among older adults with hypertension.

A National Catalog of Mapped Short-Form Six-Dimension Utility Scores for Chronic Conditions in the United States From 2010 to 2015

OBJECTIVES

This study examined health preference utility weights and utility decrements associated with different types of chronic conditions in the United States.

METHODS

We used the 2010-2015 Medical Expenditure Panel Survey data for persons aged ≥ 18 years with 12-Item Short-Form Survey Physical and Mental Component Summary scores. 12-Item Short-Form Survey scores were converted to Short-Form Six-Dimension (SF-6D) preference scores to measure utilities of different chronic diseases. We used the Clinical Classification Code to identify 30 chronic diseases from 12 categories, such as cardiovascular diseases, cerebrovascular diseases, hypertension, hyperlipidemia, obesity, cancers, musculoskeletal diseases, endocrine or metabolic diseases, oral diseases, respiratory diseases, and mental disorders. A generalized linear model was used to quantify the utility decrements for 30 chronic diseases, controlling for demographic characteristics.

RESULTS

We identified 132 737 adults (mean age 47.2 years, 52.2% female, 80% white); 73% had at least one identified chronic disease, and the mean SF-6D was 0.786. Among 30 chronic diseases, the unadjusted mean SF-6D scores of patients with cognitive disorder (0.607) were the lowest, followed by congestive heart failure (0.629), rheumatoid arthritis (0.654), and lung cancer (0.662). After controlling for demographic variables (ie, age, sex) and comorbidities, cognitive disorders (-0.116), mood disorders (-0.099), rheumatoid arthritis (-0.090), liver cancer (-0.078), and stroke (-0.063) showed the highest decrements in the SF-6D scores (P < .05).

CONCLUSIONS

This study provides a nationally representative catalog of utility weights for major chronic diseases in the US general population. The utility decrements will enable researchers to calculate the health utilities of patients with multiple comorbid diseases.

A network meta-analysis of efficacy and safety of first-line and second-line therapies for the management of metastatic renal cell carcinoma

WHAT IS KNOWN AND OBJECTIVE

Metastatic renal cell carcinoma (mRCC) is the most common type of kidney cancers. Disease-specific survival for mRCC has been significantly improved with the introduction of new targeted agents since 2005. However, there is a lack of head-to-head clinical trials comparing the efficacy between therapies. This study compared indirectly progression-free survival (PFS) and overall survival (OS) among first-line and second-line therapies in patients with mRCC using network meta-analysis (NMA).

METHODS

The PubMed, MEDLINE, Cochrane Library and Web of Science were searched to identify phase II or phase III randomized controlled trials (RCTs) of targeted and biological therapies in patients with mRCC published between January 2000 and June 2020. The Bayesian fixed-effect NMA was performed to evaluate relative PFS and OS of first-line and second-line therapies of axitinib, bevacizumab, cabozantinib, everolimus, lenvatinib, nivolumab, ipilimumab, pazopanib, sorafenib, sunitinib, temsirolimus, tivozanib, avelumab and pembrolizumab, which were approved by the Food and Drug Administration or European Medicines Agency. End points were compared using hazard ratio (HR) and 95% credible interval (CrI). The surface under the cumulative ranking curve (SUCRA) was estimated to assess the probability of being the best treatment.

RESULTS AND DISCUSSION

A total of 26 RCTs (first line: 19, second line: 9) with 13 893 patients were included in the NMA. For the first-line therapy, cabozantinib was associated with the highest improved PFS (HR = 0.26, 95% CrI = 0.14-0.44) followed by avelumab + axitinib and pembrolizumab + axitinib (HR = 0.27, SUCRA = 90%). Pembrolizumab + axitinib had a high likelihood of being the preferred treatment when using OS as the outcome measure (HR = 0.41, 95% CrI = 0.16-0.85). Avelumab + axitinib had the lowest HR compared with placebo + interferon on discontinuations due to AE (HR = 1.04, 95% CrI = 0.54-1.86). For second-line therapy, cabozantinib was identified as the most effective treatment option when assessing PFS (HR = 0.17, 95% CrI = 0.12-0.24). Axitinib had the lowest HR of OS and discontinuation due to AE (HR = 0.54, 95% CrI = 0.40-0.71; HR = 0.98, 95% CrI = 0.42-1.97, respectively). Pazopanib was the second choice in terms of OS (HR = 0.56, 95% CrI = 0.28-1.00; SUCRA = 76%) compared with placebo.

WHAT IS NEW AND CONCLUSION

With respect to PFS and OS improvement, cabozantinib, avelumab + axitinib and pembrolizumab + axitinib are likely to be the preferred options for the first-line therapy and cabozantinib and axitinib for the second-line therapy in the management of mRCC. Regarding safety, avelumab + axitinib and temsirolimus were considered preferred treatment options in first-line and second-line therapies. More future research is needed to establish subgroup analyses, allowing evaluation of the impact of some of the differences in patient characteristics, including treatment effect modifiers.

Hyperattenuating lesions after mechanical thrombectomy in acute ischaemic stroke: factors predicting symptomatic haemorrhage and clinical outcomes

AIM

To evaluate the clinical significance of hyperattenuating lesions on CT after mechanical thrombectomy for acute ischaemic stroke, and to identify imaging factors that predict symptomatic haemorrhage and unfavourable outcomes.

MATERIALS AND METHODS

Seventy-eight patients with acute ischaemic stroke in the anterior circulation who underwent mechanical thrombectomy were evaluated. All patients underwent post-interventional unenhanced computed tomography (CT) within 24 h and follow-up CT or magnetic resonance imaging (MRI) within 7 days. Baseline characteristics and clinical outcomes were compared between patients with and without hyperattenuating lesions. In patients with hyperattenuating lesions, clinical and imaging factors that predict symptomatic haemorrhage and unfavourable outcomes were determined.

RESULTS

Fifty-six of 78 patients (71.8%) demonstrated hyperattenuating lesions on post-interventional CT. Patients with hyperattenuating lesions showed lower Alberta Stroke Program Early CT score (ASPECTS), persistent/symptomatic haemorrhage, and unfavourable outcomes than those without. In patients with hyperattenuating lesions, larger hyperattenuating lesion volume (>21.3 ml; OR, 55.60, p<0.001) and perilesional oedema (OR, 46.04, p=0.015) were independent factors predicting symptomatic haemorrhage. Older age (OR, 1.2, p=0.006) and lower ASPECTS (OR, 0.45, p=0.046) were independent factors predicting unfavourable outcomes in patients with hyperattenuating lesions. Adding the volume of the hyperattenuating lesion to age and ASPECTS increased the predictive performance of unfavourable outcomes (area under the curve 0.874 versus 0.934, p=0.043).

CONCLUSIONS

Hyperattenuating lesions on post-interventional CT are associated with increased risk of symptomatic haemorrhage and unfavourable outcomes. Larger hyperattenuating lesion volume is an independent factor of symptomatic haemorrhage and it has added predictive value for unfavourable outcomes.

Association between body mass index and stroke severity in acute ischaemic stroke with non-valvular atrial fibrillation

BACKGROUND AND PURPOSE

The objective of this study was to investigate the association between body mass index (BMI) and both initial stroke severity at presentation and functional outcomes after acute ischaemic stroke (AIS) in patients with non-valvular atrial fibrillation (NVAF).

METHODS

Patients were categorized on the basis of their BMI into underweight (BMI <18.5, n = 111), normal (18.5 ≤ BMI <25, n = 1036) and overweight to obese (BMI ≥25, n = 472) groups. Initial stroke severity was assessed using the National Institutes of Health Stroke Scale (NIHSS) score and functional outcomes were assessed using the modified Rankin Scale score at discharge. The differences in stroke severity and functional outcomes were compared between groups using robust log-linear regression with a Poisson distribution and binary logistic regression analysis.

RESULTS

A total of 1619 AIS patients with NVAF from six hospitals were included. Compared with the NIHSS scores [median 5, interquartile range (IQR) 2-14] of normal-weight patients, the NIHSS scores (median 9, IQR 4-19) of underweight patients were more likely to be higher, whereas those of overweight to obese patients were lower (median 4, IQR 1-12) (P < 0.001). In terms of functional outcomes after stroke, underweight patients had a higher risk of poor functional outcomes (odds ratio 1.78, 95% confidence interval 1.09-2.56, P = 0.01) but overweight to obese patients had no significant difference in functional outcomes compared with normal-weight patients.

CONCLUSION

An inverse association was found between BMI and stroke severity in AIS patients with NVAF. This suggests the presence of an obesity paradox for short-term outcomes in patients with NVAF.

Comparison of Prostaglandin Analog Treatment Patterns in Glaucoma and Ocular Hypertension

BACKGROUND

Prostaglandin analogs (PGAs) are considered an initial therapy to manage increased intraocular pressure (IOP) for patients with glaucoma. When the initial PGA treatment fails to lower IOP adequately, the patient may add or change medications or have surgery/laser treatment.

OBJECTIVE

To compare medication adherence, duration of therapy, and treatment patterns among 3 PGAs-latanoprost, travoprost, and bimatoprost-as initial therapies for patients with glaucoma or ocular hypertension.

METHODS

This was a retrospective cohort study using administrative claims data. The cohort consisted of patients newly diagnosed with glaucoma or ocular hypertension with at least 1 prescription claim for latanoprost, travoprost, or bimatoprost and enrolled in a Medicare Advantage plan between 2007 and 2012. The 24-month medication possession ratio (MPR) was used to measure medication adherence. Discontinuation of first-line PGA therapy was defined as nonpersistence (90-day gap allowance) of the index PGA or a change in therapy during the 24-month follow-up period. Types of second-line therapy (i.e., switch, addition, and surgery) were identified. The 1:1:1 propensity score matching was used.

RESULTS

Patients who met the inclusion criteria were propensity score matched, resulting in 1,296 patients per PGA group. Latanoprost users showed higher adherence (50.1%) than travoprost (48.8%) and bimatoprost (43.0%) users. The latanoprost and travoprost groups had significantly higher MPRs than bimatoprost (P < 0.0001). The latanoprost group showed significantly longer duration of first-line therapy (372 days) than the bimatoprost group (343 days; P = 0.003) but not the travoprost group (361 days). After controlling for demographic and clinical characteristics, a Cox proportional hazards model showed that the travoprost and bimatoprost groups had a higher risk of discontinuation of first-line therapy than the latanoprost group (P < 0.0001). The percentage of patients continuing on the index PGA without treatment pattern change (i.e., switches, additions, and surgery) was higher for latanoprost users (52.9%) compared with travoprost (39.0%) or bimatoprost users (42.1%; P < 0.001).

CONCLUSIONS

Patients who used latanoprost as their initial therapy were more likely to adhere and persist to the index PGA compared with bimatoprost users. The latanoprost group demonstrated a lower risk of discontinuing first-line therapy than the travoprost and bimatoprost groups. The results may assist ophthalmologists in determining the optimal management of this patient population with respect to treatment patterns.

DISCLOSURES

No outside funding supported this study. All authors except Heo and Nair are employed by The University of Texas at Austin College of Pharmacy. Heo was with the Health Outcomes Division, The University of Texas at Austin College of Pharmacy during a portion of this study and is employed by Genesis Research. Nair is employed by Humana. The authors have no financial relationships relevant to this article to disclose. This study was presented as a poster at the 2016 International Society for Pharmacoeconomics and Outcomes Research Annual Meeting, May 2016, Washington, DC.

Increased Fracture Risk with Furosemide Use in Children with Congenital Heart Disease

OBJECTIVES

To determine the association of furosemide therapy with the incidence of bone fractures in children with congenital heart disease.

STUDY DESIGN

We conducted a retrospective cohort study with data extracted from the 2008-2014 Texas Medicaid databases. Pediatric patients aged <12 years diagnosed with congenital heart disease, cardiomyopathy, or heart failure were included. Patients taking furosemide were categorized into a furosemide-adherent group (medication possession ratio of ≥70%), and a furosemide-nonadherent group (medication possession ratio of <70%). A third group of patients was matched to the furosemide user groups by using propensity score matching. A multivariate logistic regression and Cox proportional hazard model with a Kaplan-Meier plot (time-to-fracture) were used to compare the 3 groups, controlling for baseline demographics and clinical characteristics.

RESULTS

After matching, 3912 patients (furosemide adherent, n = 254; furosemide nonadherent, n = 724; no furosemide, n = 2934) were identified. The incidence of fractures was highest for the furosemide-adherent group (9.1%; 23 of 254), followed by the furosemide-nonadherent group (7.2%; 52 of 724), which were both higher than for patients who did not receive furosemide (5.0%; 148 of 2934) (P < .001). Using logistic regression, both furosemide groups were more likely to have fractures than the no furosemide group: furosemide-adherent OR of 1.9 (95% CI, 1.17-2.98; P = .009); furosemide nonadherent OR of 1.5 (95% CI, 1.10-2.14; P = .01). In the Cox proportional hazard model, the risk of fractures for the furosemide-adherent group was significantly higher compared with the no furosemide group (HR, 1.6; 95% CI, 1.00-2.42; P = .04).

CONCLUSIONS

Furosemide therapy, even with nonconsistent dosing, was associated with an increased risk of bone fractures in children with congenital heart disease.

Prediction of Change in Prescription Ingredient Costs and Co-payment Rates under a Reference Pricing System in South Korea

BACKGROUND

The reference pricing system (RPS) establishes reference prices within interchangeable reference groupings. For drugs priced higher than the reference point, patients pay the difference between the reference price and the total price.

OBJECTIVES

To predict potential changes in prescription ingredient costs and co-payment rates after implementation of an RPS in South Korea.

METHODS

Korean National Health Insurance claims data were used as a baseline to develop possible RPS models. Five components of a potential RPS policy were varied: reference groupings, reference pricing methods, co-pay reduction programs, manufacturer price reductions, and increased drug substitutions. The potential changes for prescription ingredient costs and co-payment rates were predicted for the various scenarios.

RESULTS

It was predicted that transferring the difference (total price minus reference price) from the insurer to patients would reduce ingredient costs from 1.4% to 22.8% for the third-party payer (government), but patient co-payment rates would increase from a baseline of 20.4% to 22.0% using chemical groupings and to 25.0% using therapeutic groupings. Savings rates in prescription ingredient costs (government and patient combined) were predicted to range from 1.6% to 13.7% depending on various scenarios. Although the co-payment rate would increase, a 15% price reduction by manufacturers coupled with a substitution rate of 30% would result in a decrease in the co-payment amount (change in absolute dollars vs. change in rates).

CONCLUSIONS

Our models predicted that the implementation of RPS in South Korea would lead to savings in ingredient costs for the third-party payer and co-payments for patients with potential scenarios.

Prognostic significance of volume-based 18F-FDG PET/CT parameter in patients with surgically resected non-small cell lung cancer. Comparison with immunohistochemical biomarkers

AIM

We investigated the prognostic value of volume-based 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography (PET) parameters compared with other factors including several immunohistochemical biomarkers in patients with surgically resected non-small cell lung cancer (NSCLC).

PATIENTS, METHODS

STUDY PARTICIPANTS

290 patients with surgically resected and histopathologically confirmed NSCLC. The maxmum standardized uptake value (SUVmax) and metabolic tumour volume (MTV) of the primary tumour were obtained on 18F-FDG PET/ computed tomography (CT) for initial staging and Ki-67 labeling index (LI), p16, CD31 and cyclin E were evaluated in the primary tumours by immunohistochemical staining. Survival analyses for variables including PET parameters, immunohistochemical biomarker and other clinical factors were performed using the Kaplan-Meier method and Cox proportional hazards regression analysis.

RESULTS

In univariate analyses, tumour stage, tumour size, and MTV were significant prognostic factors for decreased overall survival (OS) and disease-free survival (DFS). Multivariate analyses showed MTV and tumour stage were significant predictors of poor OS (MTV, hazard ratio (HR) = 1.135, p = 0.015; stage, HR = 0.644, p = 0.025) and DFS (MTV, HR = 1.128, p = 0.043; stage, HR = 0.541, p = 0.009).

CONCLUSION

The MTV of primary tumours is a significant prognostic factor for survival along with tumour stage in patients with surgically resected NSCLC. The MTV can predict OS and DFS better than immunohistochemical biomarkers.

Differential impact of unrecognised brain infarction on stroke outcome in non-valvular atrial fibrillation

There has been little information regarding the impact of unrecognised brain infarctions (UBIs) on stroke outcome in patients with non-valvular atrial fibrillation (NVAF). By using volumetric analysis of ischaemic lesions, we evaluated the potential impact of UBIs on clinical outcome according to their presence and categorised type. This study enrolled 631 patients with NVAF having no clinical stroke history. UBIs were categorised into three types as territorial, lacunar, or subcortical. We collected stroke severity, functional outcome at three months, and the total volume of UBIs and acute infarction lesions. We investigated the association between clinical outcome and the type or volume of UBI, using a linear mixed model and logistic regression analysis. UBIs were detected in 285 (45.2 %) patients; territorial UBIs were observed in 24.4 % of patients (154/631), lacunar UBIs in 25 % (158/631), and subcortical UBIs in 15.7 % (99/631). Although initial stroke severity was not different between patients with UBIs and those without, those with UBIs had less improvement during hospitalisation, leading to poorer outcome at three months. Among the three types of UBIs, only territorial UBIs were associated with poor outcome, especially in patients with relatively smaller acute infarction volume. UBIs, in particular, territorial UBIs, may be considered as predictors for poor outcome after ischaemic stroke in patients with NVAF. Our results suggest that the impact of UBIs on clinical outcome differs according to the type of UBIs and the acute stroke severity.

Comparison of stent retriever and intra-arterial fibrinolysis in patients with acute ischaemic stroke

BACKGROUND AND PURPOSE

Although the stent retriever (SR) has shown a better reperfusion rate and clinical outcome than the older generation mechanical clot retrieval device, it is uncertain whether the SR is superior to intra-arterial fibrinolysis (IAF).

METHODS

Ischaemic stroke patients who were treated with SR or IAF as initial endovascular treatment modality for unilateral arterial occlusion in the anterior circulation were included. Successful reperfusion was defined as Thrombolysis in Cerebral Infarction grade ≥2b. A favourable clinical outcome was defined as a modified Rankin Score ≤2 at 3 months.

RESULTS

Between January 2009 and May 2012, 55 patients were treated with SR and 50 patients were treated with IAF. The baseline characteristics were similar between the two groups except for the occlusion site and rescue treatment. In binary logistic regression analysis adjusted for the occlusion site and rescue treatment, SR was independently associated with increased successful reperfusion [82.0% vs. 47.3%; odds ratio (OR) 5.21; 95% confidence interval (CI) 1.92-14.14) and a more favourable clinical outcome at 3 months (54.0% vs. 43.6%; OR 3.40; 95% CI 1.31-8.84). The frequency of symptomatic intracranial haemorrhage and mortality at 3 months was not different between the two groups.

CONCLUSIONS

Stent retriever was as safe as and more effective than IAF. Our findings suggest that SR may be considered as an initial modality rather than IAF in acute stroke patients who undergo endovascular treatment.

The association between asymptomatic coronary artery disease and CHADS2 and CHA2 DS2 -VASc scores in patients with stroke

BACKGROUND AND PURPOSE

CHADS2 and CHA2 DS2 -VASc scores are measurement tools that stratify thromboembolic risk in patients with non-valvular atrial fibrillation, and are predictive of cerebral atherosclerosis, fatal stroke and ischaemic heart disease. Patients with higher CHADS2 and CHA2 DS2 -VASc scores are more likely to have had an akinetic/hypokinetic left ventricular segment or a recent myocardial infarction, all of which are associated with coronary artery disease (CAD). Most of the CHADS2 score components are also risk factors for atherosclerosis. Thus, CHADS2 and CHA2 DS2 -VASc scores may be predictive of CAD.

METHODS

In all, 1733 consecutive patients with acute ischaemic stroke who underwent multi-slice computed tomography coronary angiography were enrolled. The association of CHADS2 and CHA2 DS2 -VASc scores with the presence and severity of CAD was investigated.

RESULTS

Of the 1733 patients, 1220 patients (70.4%) had any degree of CAD and 576 (33.3%) had significant CAD (≥ 50% stenosis in at least one coronary artery). As the CHADS2 and CHA2 DS2 -VASc scores increased, the presence of CAD also increased (P < 0.001). The severity of CAD was correlated with CHADS2 score (Spearman coefficient 0.229, P < 0.001) and CHA2 DS2 -VASc score (Spearman coefficient 0.261, P < 0.001). In multivariate analysis, after adjusting for confounding factors, CHADS2 and CHA2 DS2 -VASc scores ≥2 were independently associated with CAD. The CHA2 DS2 -VASc score was a better predictor of the presence of CAD than the CHADS2 score on area under the curve analysis.

CONCLUSION

CHADS2 and CHA2 DS2 -VASc scores were predictive of the presence and severity of CAD in patients with stroke. When a patient has high CHADS2 or CHA2 DS2 -VASc scores, physicians should consider coronary artery evaluation.

The frequency of cerebral microbleeds increases with CHADS(2) scores in stroke patients with non-valvular atrial fibrillation

BACKGROUND AND PURPOSE

Cerebral microbleeds (CMBs) are extravasations of blood from lipohyalinized or amyloid angiopathic cerebral arterioles, and the presence and numbers of CMBs are significantly associated with the development of oral anticoagulation (OA)-related intracranial haemorrhage (ICH). The aim of this study was to investigate whether there is a difference in CMBs burden according to CHADS(2) scores or CHA(2) DS(2) -VASc scores in non-valvular atrial fibrillation (NVAF) patients.

METHODS

We included 550 ischaemic stroke patients who had NVAF and who had undergone brain magnetic resonance imaging (MRI) with gradient-recalled echo (GRE) T2 sequences from our prospective stroke registry between January 2005 and November 2011. We calculated CHADS(2) scores and CHA(2) DS(2) -VASc scores for all patients based on their underlying cardiovascular diseases. The presence, location and number of CMBs were assessed in each patient. We also investigated whether the CMBs were actually associated with the development of ICH during follow-up.

RESULTS

The mean patient age was 70.4 ± 10.5 years, and 324 (58.9%) patients were men. One-hundred and seventy-three patients (31.5%) had CMBs detected on GRE MRI. Higher CHADS(2) scores or CHA(2) DS(2) -VASc scores were strongly associated with the presence and number of CMBs. During follow-up of median 3.1 ± 1.6 years, the presence of CMBs was independently associated with the development of ICH, whilst the CHADS(2) scores or CHA(2) DS(2) -VASc scores were not.

CONCLUSIONS

Considering the positive association between the presence of CMBs and OA-related ICH, our results suggest that the increase in ICH in high-risk groups during OA may be related to an increased burden of CMBs.

Magnesium-doped zinc oxide electrochemically grown on fluorine-doped tin oxide substrate

Nanostructures of magnesium (Mg) doped Zinc oxide (ZnO) were successfully deposited on conducting fluorine-doped tin oxide (FTO) coated glass plates by cathodic electrochemical deposition method at different potentials and temperature conditions. The deposited samples were characterized by XRD and SEM techniques to confirm their structures, morphologies and optical properties. These measurements show that Mg doped ZnO has a wurtzite structure and that the strongest intensity of the (002) peak is found at 60 degrees C and -1.0 V. Tunable transmittance of Mg doped ZnO has a band gap energy from 3.45 eV to 3.82 eV, which is the direct evidence of doping.

Use of a handheld, computerized device as a decision support tool for stroke classification

BACKGROUND

The Trial of ORG 10172 in Acute Stroke Treatment (TOAST) classification has been widely used to determine etiology of ischemic stroke. However, interrater reliability is known to be modest. The complexity of abstraction and the interpretation of various clinical and laboratory data might limit the accuracy of the TOAST classification. In this study, we developed a computerized clinical decision support system for stroke classification that can be used in a handheld device and tested whether this system can improve diagnostic accuracy and reliability.

METHODS

Based on the TOAST classification, a logical algorithm was developed and implemented on a handheld device, named iTOAST. After answering six questions using the touch interface, the stroke subtype result is displayed on the screen. Four neurology residents were randomly assigned to classify stroke subtypes using iTOAST or the conventional method (cTOAST). Using a crossover design, they classified the stroke subtypes of 70 patients. The standard subtypes were determined by three stroke experts. Correlated kappa coefficients using iTOAST compared with cTOAST were determined.

RESULTS

The kappa (SE) value of iTOAST [0.790 (0.041), 95% CI: 0.707-0.870] was higher than that of cTOAST [0.692 (0.046), 95% CI: 0.600-0.782] (P<0.001). Neither sequence (P=0.857) nor period effect (P=0.999) was observed.

CONCLUSIONS

The stroke classification tool using a handheld, computerized device was easy, accurate, and reliable over the conventional method. It may have additional benefit because a handheld, computerized device is accessible anytime and anywhere.

Early neurological outcomes according to CHADS2 score in stroke patients with non-valvular atrial fibrillation

BACKGROUND AND PURPOSE

A higher CHADS(2) score or CHA(2)DS(2)-VASc score is associated with an increased risk of ischaemic stroke in patients with non-valvular atrial fibrillation (NVAF). However, there are no data regarding early neurological outcomes after stroke according to the risk levels.

METHODS

In this study, a total of 649 stroke patients with NVAF were enrolled and categorized into three groups: low-risk (CHADS(2) score of 0-1), moderate-risk (CHADS(2) score 2-3), or high-risk group (CHADS(2) score ≥4). CHA(2)DS(2)-VASc score was divided into four groups including 0-1, 2-3, 4-5, and ≥6. We investigated whether there were differences in initial stroke severity, early neurological outcome, and infarct size according to CHADS(2) score or CHA(2)DS(2)-VASc score in stroke patients with NVAF.

RESULTS

The initial National Institutes of Health Stroke Scale (NIHSS) score was highest in high-risk group [9.5, interquartile range (IQR) 4-18], followed by moderate-risk (8, IQR 2-17) and low-risk group (6, IQR 2-15) (P=0.012). Likewise, initial stroke severity increased in a positive fashion with increasing the CHA(2)DS(2)-VASc score. During hospitalization, those in the high-risk group or higher CHA(2)DS(2)-VASc score had less improvement in their NIHSS score. Furthermore, early neurological deterioration (END) developed more frequently as CHADS(2) score or CHA(2)DS(2)-VASc score increased. Multivariate analysis showed being in the high-risk group was independently associated with END (OR 2.129, 95% CI 1.013-4.477).

CONCLUSIONS

Our data indicate that patients with NVAF and higher CHADS(2) score or CHA(2)DS(2)-VASc score are more likely to develop severe stroke and a worse clinical course is expected in these patients after stroke presentation.

Effect of warfarin withdrawal on thrombolytic treatment in patients with ischaemic stroke

BACKGROUND AND PURPOSE

  Abruptly discontinuing warfarin may induce a rebound prothrombotic state. Thrombolytic agents may also paradoxically induce prothrombotic conditions, which include platelet activation and thrombin generation. Therefore, prothrombotic states may be enhanced by withdrawing warfarin in patients under thrombolytic treatment. This study was aimed to determine whether patients with warfarin withdrawal have different clinical outcomes from those without warfarin use after thrombolytic treatment.

METHODS

  A total of 148 consecutive patients with atrial fibrillation who were not on anticoagulants at admission and who received thrombolysis were included in this study. We compared the outcomes between a warfarin withdrawal group and a no-warfarin group.

RESULTS

  Fourteen patients (9.5%) were included in the warfarin withdrawal group. Although baseline National Institute of Health Stroke Scale (NIHSS) scores, recanalization rates, and hemorrhage frequencies did not differ between the groups, the warfarin withdrawal group showed poorer outcomes. Increased NIHSS scores during the first 7days were more frequent in the warfarin withdrawal group (57.1% vs. 26.9%, P=0.029). The median percent improvement in NIHSS scores at 24h after thrombolysis was also lower in the warfarin withdrawal group. After adjusting for covariates, warfarin withdrawal was a strong predictor of poor functional outcome at 3months (modified Rankin score≥3) (odds ratio, 17.067, 95% CI 2.703-107.748).

CONCLUSIONS

  Discontinuing warfarin was associated with early neurologic deterioration and poor long-term outcomes after thrombolytic treatment.

Failure of complete recanalization is associated with poor outcome after cardioembolic stroke

BACKGROUND

  Recanalization is strongly associated with outcomes after thrombolytic treatment. Cardiac emboli are known as better response to fibrinolytic agents because they are fibrin-rich; however, cardioembolic stroke itself is associated with poor outcomes and high mortality. Completeness of recanalization may therefore affect the outcome of cardioembolic stroke. We investigated whether degree of recanalization influences outcomes following fibrinolytic therapy in cardioembolic stroke.

METHODS

  Consecutive stroke patients with relevant artery occlusions on baseline CT angiography who had received thrombolytic treatment were enrolled. Completeness of recanalization was assessed by the Thrombolysis in Myocardial Infarction (TIMI) grade, which was compared between patients with and without cardiac sources of embolism (CSE). We also investigated independent predictors of poor outcome (modified Rankin scale score 3-6) at 3 months.

RESULTS

  Of the 127 patients enrolled, 65 (51%) had one or more CSE. Although the overall recanalization rates (TIMI 2 or 3) in patients with CSE (65%) and patients without CSE (68%) were similar (P=0.710), patients with CSE were less likely to show complete recanalization (TIMI 3) compared with those without CSE (19% vs. 39%, P=0.011). Multivariate analysis revealed that CSE was associated with failure of complete recanalization (OR 2.809, 95% CI 1.097-7.192) and was an independent predictor of poor outcome at 3months (OR 3.629, 95% CI 1.205-8.869).

CONCLUSIONS

  In cardioembolic strokes, failure of complete recanalization following thrombolytic therapy was frequent and was associated with poor outcome after thrombolysis.

The different infarct patterns between adulthood-onset and childhood-onset moyamoya disease

BACKGROUND AND PURPOSE

The pattern of infarctions based on the findings of diffusion-weighted image was assessed, and it was also investigated whether there are any age-specific differences in patients with moyamoya disease (MMD).

METHODS

The subjects were 66 consecutive patients with MMD who had an acute cerebral infarction. Each ischaemic lesion was categorised into one of seven patterns (gyral, atypical territorial, honeycomb, classic territorial, multiple-dot, borderzone, deep lacunar) based on diffusion-weighted image findings. The patterns were compared between adulthood-onset MMD (A-MMD, ≥20 years old, 34 patients) and childhood/adolescent-onset MMD (C-MMD, <20 years old, 32 patients) according to their ages of infarct presentation.

RESULTS

A total of 91 infarct patterns were observed from 66 patients. The gyral, atypical territorial, and honeycomb patterns, which are not usually seen in conventional stroke patients, were common in MMD (68.1%). Among all patterns, a gyral pattern was most common (40/91, 44.0%). Borderzone and deep lacunar patterns were infrequent. Gyral and borderzone patterns were more frequently seen in the C-MMD group, whereas a honeycomb pattern was not seen in young patients. Honeycomb pattern was more common at advanced vascular stages. Infarctions confined to the cortex were more common in the C-MMD group (26/32, 75.0%) than in A-MMD patients (14/34, 41.2%).

CONCLUSIONS

Moyamoya disease showed various characteristic and age-specific infarct patterns. Different infarct patterns between the A-MMD and C-MMD groups may be associated with age-specific vulnerability of the brain to ischaemia, stage of arteriopathy or changes of abnormal collateral pathways.

Comparison of the characteristics for in-hospital and out-of-hospital ischaemic strokes

BACKGROUND AND PURPOSE

Patients who are being admitted to a hospital due to diseases other than stroke may develop a stroke (in-hospital stroke; IHS).

METHODS

We enrolled 111 consecutive patients who developed IHS outside a neurology ward during a 5-year period at a single hospital. The frequency, characteristics, and outcomes for IHS patients were compared with patients who develop ischaemic stroke outside of the hospital (out-of-hospital stroke; OHS).

RESULTS

Forty-six percent of IHS occurred in the department of cardiology or cardiovascular surgery and 60% were associated with surgery or procedures. In comparison with the OHS patient group, the IHS patient group showed an increased frequency of cardiac disease, leukocytosis, and anemia. Cardioembolism, stroke of other determined etiologies, and an incomplete evaluation were more common in the IHS group, whereas large artery atherosclerosis was more frequent in the OHS group. The IHS group had up to a 10-fold higher mortality than the OHS group, with sepsis being the most common cause of death in the IHS group.

CONCLUSIONS

IHS has distinct etiologies and stroke mechanisms from OHS. The prevention and management of infection could decrease mortality in IHS patients.

Thrombus volume comparison between patients with and without hyperattenuated artery sign on CT

BACKGROUND AND PURPOSE

Although the hyperattenuated middle cerebral artery sign is known to be related to acute infarction, the volume of clot associated with it is not known. We investigated whether the presence or absence of hyperattenuated artery sign (HAS) on noncontrast CT (NCCT) can predict the thrombus volume.

MATERIALS AND METHODS

We enrolled 90 consecutive patients with acute infarction who underwent both 5- and 1.25-mm NCCT and CT angiography (CTA). HAS was determined on 5-mm NCCT retrospectively. According to the location of thrombi, the patients were classified into ICA (ICA terminus/ICA and others), M1 (M1/both M1 and M2), and M2 (M2) groups. Thrombus volumes were measured by 1.25-mm NCCT and were compared between patients with and without HAS.

RESULTS

Occlusion of major arteries was seen on CTA in 78 patients. HAS was found in 46 patients (59.0%). The mean thrombus volume was significantly larger in patients with HAS than in those without except for the M2 group (ICA group: [n = 14], 188.7 +/- 122.5 mm(3) versus 39.4 +/- 12.1 mm(3) [P = .022]; M1 group: [n = 42], 128.1 +/- 119.2 versus 56.8 +/- 32.5 [P = .005]; M2 group: [n = 22], 34.7 +/- 32.2 versus 20.0 +/- 20.0 [P = .18]). Thrombus volumes determined by receiver operating characteristic curve analysis were 52.36 mm(3) in the ICA group (sensitivity, 90.9%; specificity, 100%) and 53.96 mm(3) in the M1 group (sensitivity, 88.0%; specificity, 58.8%).

CONCLUSION

Thrombus volumes were significantly larger in patients with HAS than in those without in ICA and M1 occlusions. The detection of HAS may provide an idea concerning rapid and dichotomized estimation of thrombus volume, which may be helpful for treatment decisions in potential candidates for thrombolysis.

Prediction of thrombolytic efficacy in acute ischemic stroke using thin-section noncontrast CT

Thin-section noncontrast CT (NCT) can detect thrombi in large arteries and can provide a measure of thrombus composition based on Hounsfield Units (HU). A study using polyethylene tubes as a model of intracranial arteries concluded that the HUs of platelet-rich thrombi are lower than those of erythrocyte-rich thrombi. Thrombus HUs were measured by NCT in 34 patients with acute ischemic stroke before thrombolysis. Thrombi with lower HU counts were resistant to thrombolytics.

Association of aortic plaque with intracranial atherosclerosis in patients with stroke

OBJECTIVE

To determine whether there is a relationship between aortic plaques and intracranial (IC) atherosclerosis.

METHODS

We reviewed 922 patients with stroke who had both transesophageal echocardiography and cerebral angiography. The plaques of these patients were classified as either complex aortic plaques (CAP), which protruded > or =4 mm or were present as mobile lesions in the proximal aorta, or simple aortic plaques (SAP), which were <4 mm or present in the descending aorta. Cerebral artery atherosclerosis was classified as either an IC or extracranial (EC) atherosclerosis.

RESULTS

Among the 922 patients, we found aortic plaques in 237 patients (26%). There were 111 (47%) patients of SAP, 74 (31%) patients with CAP, and 52 (22%) patients that had both SAP and CAP. Angiography showed IC or EC atherosclerosis in 511 patients (55%). The presence of aortic plaques was significantly associated with IC or EC atherosclerosis. The significance appeared to be due to the strong association between the presence of SAP and IC atherosclerosis (51% SAP vs 35% no plaques; odds ratio = 1.94, 95% CI: 1.17 to 3.21). In the multiple logistic regression analysis, SAP were independent predictors of IC atherosclerosis

CONCLUSIONS

The presence of simple aortic plaques may be a marker of advanced vascular disease. Detection of simple aortic plaques during transesophageal echocardiography may have clinical implications because patients with these plaques frequently had concomitant intracranial atherosclerosis, a risk factor for stroke.

Hemodynamic changes in limb shaking TIA associated with anterior cerebral artery stenosis

Limb shaking TIA is a rare but well-known feature of severe carotid artery stenosis. The authors report a patient who developed recurrent shaking movements of a leg. An angiogram showed the focal stenosis of the anterior cerebral artery. Ictal and postacetazolamide SPECT scans suggested a local hyperfunction of cortical neurons and an impaired hemodynamic reserve in the vicinity of the ischemic area.

Cloning and expression of a novel esterase gene cpoA from Burkholderia cepacia

AIMS

To screen and clone a novel enzyme with specific activity for the resolution of (R)-beta-acetylmercaptoisobutyrate (RAM) from (R,S)-beta-acetylmercaptoisobutyrate [(R,S)-ester].

METHODS AND RESULTS

A micro-organism that produces a novel esterase was isolated and identified as the bacterium Burkholderia cepacia by using the analysis of cellular fatty acids, Biolog automated microbial identification/characterization system, and 16S rRNA gene sequence analysis. A novel esterase gene was cloned from the chromosomal DNA of B. cepacia and was designated as cpoA. The cpoA encodes a polypeptide of 273 amino acids which shows a strong sequence homology with many bacterial nonhaeme chloroperoxidases. In addition, a typical serine-hydrolase motif, Gly-X-Ser-X-Gly, and the highly conserved catalytic triad, Ser95, Asp224, and His253, were identified in the deduced amino acid sequence of cpoA by multiple sequence alignment.

CONCLUSION

The cpoA cloned from B. cepacia encodes a novel esterase which is highly related to the nonhaeme chloroperoxidases.

SIGNIFICANCE AND IMPACT OF THE STUDY

This is the first report that describes the isolation and cloning of a serine esterase gene from B. cepacia, which is useful in the chiral resolution of (R,S)-ester. The cloned gene will allow additional research on the bifunctionality of the enzyme with esterase and chloroperoxidase activity at the structural and functional levels.

Yonsei Stroke Registry. Analysis of 1,000 patients with acute cerebral infarctions

BACKGROUND AND PURPOSE

The hospital-based stroke registry is a well-established method useful for understanding diverse clinical characteristics of stroke related to geographical, racial or environmental differences. We analyzed the data from 1,000 patients with acute cerebral infarctions registered with the Yonsei Stroke Registry (YSR) which is the first prospective hospital-based observational study in Korea.

METHODS

All patients had cerebral infarctions and presented within 7 days of onset. CT or MRI was performed in all patients and a vascular imaging study (digital subtraction or magnetic resonance angiography) was conducted in 53.9% of the patients. Subtype classification was made through a consensus approach based on the strict application of TOAST criteria.

RESULTS

The mean age of patients was 62 +/- 12 years, and 60.8% were males. Undetermined cause (UD) was the most frequent subtype (40.6%), which was followed by lacunar stroke (LS 21.5%), cardiac embolism (CE 18.3%), large-artery atherosclerosis (LAA 16.5%) and other determined causes (3.1%). Hypertension was found in 64.3%, smoking in 35.2%, diabetes mellitus in 26.9%, hypercholesterolemia in 24.1%, high hematocrit (> or = 50%) in 21.8%, clinically identified potential cardiac sources of embolism in 18.3%, a history of previous stroke in 22.0% and a history of previous transient ischemic attack in 4.7%. Recurrent stroke was associated with a higher number of risk factors (p < 0.001) and a higher incidence of LAA (p = 0.003) than the first stroke. Vertebrobasilar artery territorial infarction was found in 39.8%, which was associated with higher incidences of LAA and LS and a lower incidence of CE than carotid artery territorial lesions (p = 0.001). The 30-day mortality rate was 5.3% and cerebral herniation caused early death in 52%.

CONCLUSION

The distribution of stroke subtypes in the YSR was largely comparable with that of western registries. The highest incidence of UD might be related to the strict application of TOAST criteria.

Localization of Claude's syndrome

Although the red nucleus often has been suggested to be the lesion site responsible for Claude's syndrome, the precise localization of the syndrome is uncertain. Lesion sites were reviewed in six patients with Claude's syndrome and compared with other patients with the syndrome identified by a literature search. The findings strongly suggest that Claude's syndrome occurs because of a lesion of the superior cerebellar peduncle just below and medial to the red nucleus. Midbrain infarction and partial oculomotor nerve palsy was common.

Effect of the absence of heat shock protein 70.1 (hsp70.1) on retinal photoreceptors in normal and rd mice

The purposes of this study are to elucidate the retinal changes of heat shock protein 70.1 (hsp70.1) knockout mice and to compare them between in normal and in retinal degeneration (rd) mice. Eyes of hsp70.1 wild type (+/+) and knockout (-/-) mice in the C57BL/6 or FVB genetic backgrounds respectively, which were reared in the normal environment, were examined by fundus photography, electroretinography, light microscopy, terminal dUTP nick-end labeling (TUNEL) stain, and immunohistochemistry. In C57BL/6 mice, fundus photography showed no changes between hsp70.1+/+ and -/- mice at 1 and 6 months of age. Electroretinographic examination showed a tendency of decreased amplitude of a- and b-wave with aging in both genotype, but there were not different statistically. The ratios of the thickness of inner nuclear and outer nuclear layer to the retinal thickness were respectively decreased with aging in both genotype, but there were not different statstically. TUNEL assay showed a few positively labeled cells in the ganglion cell, inner nuclear and outer nuclear layers and the immunohistochemistry showed no immunopositivity of hsp70 in the inner segments of photoreceptor cell layer in both genotype. In rd mice, fundus photography showed a narrowing of the retinal vessels at the age of 4 weeks, however, there were no differences of retinal changes including pigment epithelial layer in both genotype. Electroretinographic examination at the postnatal 2, 3 and 4 weeks showed no differences between them. Loss of photoreceptor cell and outer nuclear layers showed no differences in both genotype. In conclusion, there were no differences of the retinal changes at least under the normal environmental condition in hsp70.1+/+ and -/- mice. These results show that hsp70.1-/- mice can be used to study the role of hsp70.1 to the external stress to the retina.

Rescue treatment with abciximab in acute ischemic stroke

In acute ischemic stroke, reocclusion after an initially successful thrombolysis treatment can occur and is associated with increased morbidity and mortality. The authors present the successful use of abciximab, a platelet glycoprotein IIb/IIIa receptor inhibitor, in a patient with a thrombotic occlusion of the proximal middle cerebral artery, which was refractory to combined IV and intra-arterial thrombolysis and percutaneous intracranial balloon angioplasty.

Rapid differential endogenous plasminogen activator expression after acute middle cerebral artery occlusion

BACKGROUND AND PURPOSE

During focal cerebral ischemia, the microvascular matrix (ECM), which participates in microvascular integrity, is degraded and lost when neurons are injured. Loss of microvascular basal lamina antigens coincides with rapid expression of select matrix metalloproteinases (MMPs). Plasminogen activators (PAs) may also play a role in ECM degradation by the generation of plasmin or by MMP activation.

METHODS

The endogenous expressions of tissue-type plasminogen activator (tPA), urokinase (uPA), and PA inhibitor-1 (PAI-1) were quantified in 10-microm frozen sections from ischemic and matched nonischemic basal ganglia and in the plasma of 34 male healthy nonhuman primates before and after middle cerebral artery occlusion (MCA:O).

RESULTS

Within the ischemic basal ganglia, tissue uPA activity and antigen increased significantly within 1 hour after MCA:O (2P<0.005). tPA activity transiently decreased 2 hours after MCA:O (2P=0.01) in concert with an increase in PAI-1 antigen (2P=0.001) but otherwise did not change. The transient decrease in free tPA antigen was marked by an increase in the tPA-PAI-1 complex (2P<0.001). No significant relations to neuronal injury or intracerebral hemorrhage were discerned.

CONCLUSIONS

The rapid increase in endogenous PA activity is mainly due to significant increases in uPA, but not tPA, within the ischemic basal ganglia after MCA:O. This increase and an increase in PAI-1 coincided with latent MMP-2 generation and microvascular ECM degeneration but not neuronal injury.

MRI features of infarcts with potential cardiac source of embolism in the Yonsei Stroke Registry (YSR), Korea

The determination of the embolic source is crucial to understanding the pathogenesis of ischemic stroke, the initiation of appropriate therapy, and the prevention of recurrent infarctions. In this study we undertook to identify the characteristic features on magnetic resonance images of patients who had suffered from stroke due to cardiac embolism (CE), as classified by TOAST (possible and probable). We retrospectively studied magnetic resonance imaging (MRI) findings of patients with ischemic stroke from the Yonsei Stroke Registry (YSR). On the basis of the TOAST classification, 92 patients were identified to have a potential cardiac source of embolism (PCSE), in which 69 patients were found to have high-risk PCSE and 23 patients medium-risk PCSE. To compare their imaging characteristics, another group of 49 patients who were found to have had a stroke due to large artery-to-artery (ATA) embolism-common or internal carotid artery (CCA, ICA)-were identified. Involvement of the simultaneous superficial and deep territories (58.7%; 6.1%, p < 0.001), and combined new anterior and old posterior circulation (15.2%; 2.0%, p = 0.016) were more frequent in PCSE than ATA embolism. Bilateral anterior hemispheric involvement was also more frequent in the PCSE group, but it did not reach statistical significance (13.0%; 4.1%, p = 0.090). ATA embolism tended to involve only superficial territories compared to PCSE (71.4%; 28.3%, p < 0.001). There were no topographic differences between the high-risk and medium-risk groups. With respect to the etiology of PCSE in our population, atrial fibrillation was the most common. Characteristic MRI features of patients with PCSE, which were not documented previously by computed tomography (CT) included: old and new, involvement of multiple different vascular territories, bilateral anterior hemisphere, as well as anterior and posterior circulation. These MRI features, together with simultaneous superficial and deep territorial involvement, help to differentiate the underlying embolic sources, whether they are cardiac or ATA in origin.

Activated microvessels express vascular endothelial growth factor and integrin alpha(v)beta3 during focal cerebral ischemia

Both vascular endothelial growth factor (VEGF) and integrin alpha(v)beta3 play roles in angiogenesis. In noncerebral vascular systems, VEGF can induce endothelial integrin alpha(v)beta3 expression. However, it is unknown whether VEGF, like integrin alpha(v)beta3, appears in the initial response of microvessels to focal brain ischemia. Their coordinate expression in microvessels of the basal ganglia after middle cerebral artery occlusion (MCAO) in the nonhuman primate model was examined quantitatively. Cells incorporating deoxyuridine triphosphate (dUTP+) by the polymerase I reaction at 1 hour (n = 3), 2 hours (n = 3), and 7 days (n = 4) after MCAO defined the ischemic core (Ic) and peripheral regions. Both VEGF and integrin alpha(v)beta3 were expressed by activated noncapillary (7.5- to 30.0-microm diameter) microvessels in the Ic region at 1 and 2 hours after MCAO. At 7 days after MCAO, the number of VEGF+, integrin alpha(v)beta3+, or proliferating cell nuclear antigen-positive microvessels had decreased within the Ic region. The expressions of VEGF, integrin alpha(v)beta3, and proliferating cell nuclear antigen were highly correlated on the same microvessels using hierarchical log-linear statistical models. Also, VEGF and subunit alpha(v) messenger ribonucleic acids were coexpressed on selected microvessels. Here, noncapillary microvessels are activated specifically early during a focal cerebral ischemic insult and rapidly express VEGF and integrin alpha(v)beta3 together.

Matrix metalloproteinases increase very early during experimental focal cerebral ischemia

Microvascular integrity is lost during focal cerebral ischemia. The degradation of the basal lamina and extracellular matrix are, in part, responsible for the loss of vascular integrity. Matrix metalloproteinases (MMPs) may play a primary role in basal lamina degradation. By using a sensitive modification of gelatin zymography, the authors investigated the activity of MMP-2 and MMP-9 in frozen 10-microm sections of ischemic and nonischemic basal ganglia and plasma samples of 27 non-human primates after middle cerebral artery occlusion/reperfusion (MCAO/R) for various periods. The gelatinolytic activities were compared with parallel cell dUTP incorporation in the ischemic zones of adjacent sections. In the brain, the integrated density of MMP-2 increased significantly by 1 hour after MCAO and was persistently elevated thereafter. Matrix metalloproteinase-2 expression was highly correlated with the extent of neuron injury and the number of injured neurons (r = 0.9763, SE = 0.004, 2P < 0.0008). Matrix metalloproteinase-9 expression only was significantly increased in subjects with hemorrhagic transformation. In plasma, only MMP-9 increased transiently at 2 hours of MCAO. These findings highlight the early potential role of MMP-2 in the degradation of basal lamina leading to neuronal injury, and an association of MMP-9 with hemorrhagic transformation after focal cerebral ischemia.